There is a guy on my local forum that has a 150 with everything for $500 obo. Pretty good deal

Don't know how far you are from Reno but if you are interested I'll send you his contact info

Otherwise, One of the big Catfish forums has an article (sorry can't remember which one) on makingyour own tanks. He personally has made over 300 tanks. Great article with lots of excellent step by step pics